Synthesis of alcohols, aldehydes, hemiacetals, hemiaminals and amines by reduction is industrially important reaction. In particular, hydrogenation using a transition metal catalyst is useful from the view point of reducing by-products, excellent operability, and safety of work and so on. Also optically active alcohols are important as physiologically active substances such as pharmaceuticals, agricultural chemicals and aromatics, and as synthetic intermediates thereof, and asymmetric hydrogenation of ketones, and hydrogenation of optically active aldehydes, optically active esters and optically active amides having a chiral point are useful as a method for producing optically active alcohols.
Also synthesis of carbonyl compounds by oxidation is industrially important. In particular, dehydrogenation using a transition metal catalyst is useful in terms of safety because it does not require an explosive substance such as a peroxide generally used as an oxidant.
Further, synthesis of N-alkylamine compounds is also industrially important reaction. In particular, N-alkylation reaction using a transition metal catalyst is useful as a safe procedure because it does not require a mutagen such as methyl iodide and dimethyl sulfate that are generally used as an alkylating agent.
As transition metal catalysts used in these reactions, heterogeneous catalysts using platinum or chromium as metal, and homogenous catalysts using ruthenium, iridium or rhodium as metal can be recited. Reaction using a heterogeneous catalyst generally requires high temperature and high pressure, and has a problem in terms of safety. Therefore, homogenous catalysts are industrially advantageous. In particular, a ruthenium catalyst is advantageous over an iridium catalyst or a rhodium catalyst in terms of costs.
As a catalyst used for hydrogenation of ketones, esters and so on, a ruthenium complex having a bis (phosphinoalkyl)amine as a tridentate ligand and having carbon monoxide as a monodentate ligand is reported (see Patent Document 1). Also, hydrogenation of amides, dehydrogenation of alcohols, and condensation between alcohols and amines using the ruthenium complex as a catalyst are also reported (see Patent Documents 2, 3 and 4). Although a ruthenium complex having a bis (phosphinoalkyl) amine as a tridentate ligand, and having tertiary phosphines as a monodentate ligand is reported, this ruthenium complex is not used as a catalyst (see Non Patent Document 1).